DEL MAR  The future expansion of Flower Hill Promenade is likely to worsen traffic jams on Via de la Valle and nearby streets, according to a recently released environmental impact report.

The report lends some support to opponents’ arguments that the project is too intense for the neighborhood. The developer says traffic is unavoidable, and adds that the project includes a much-needed high-end grocery store.

Flower Hill is a 33-year-old shopping center on Via de la Valle east of Interstate 5 and the Del Mar Fairgrounds. While it is technically in the city of San Diego, it has a Del Mar ZIP code and attracts an affluent mix of customers from Del Mar, Solana Beach and Rancho Santa Fe.

In slope-roofed buildings that show signs of wear, the mall has a theater and boutiques, including Venissimo Cheese and The Rare Earth women’s clothing store, and restaurants.

The expansion would focus mainly on the west side of the site, leaving the east-side buildings in place. The UltraStar Cinemas would be demolished and replaced with a Whole Foods Market, offices and shops. Behind those buildings would be a parking garage.

La Jolla-based Protea Properties, which bought the mall in 2002, has sought to expand it for years. The plans were scaled back twice to address community concerns. The draft environmental report was released in March and the deadline for the public to submit comments is April 26.

Rose Jabin, Flower Hill property manager, said the goal is to secure a permit from the San Diego City Council by September and begin construction in early 2011.

“We’ve been in the community doing outreach, talking to people,” Jabin said. “By and large, I think people are happy to see something new.”

She said a study by the Whole Foods grocery chain showed that people in the area served by Flower Hill leave the community to buy about $17 million a year in products they would be able to buy at the new Whole Foods.

The project would add 3,179 more cars per day to nearby roadways that are clogged already with cars at rush hour, such as Via de la Valle between San Andres Drive and El Camino Real. To improve traffic flow, Flower Hill Drive to the north of the center would be realigned. San Andres Drive on the east would be widened and a turn lane added. The developer would be required to pay up to $3.8 million toward future traffic improvements, such as widening part of Via de la Valle.

Other environmental issues identified in the report include:

•Construction could disrupt the raptor-nesting season. Wildlife monitoring would be required.

•Demolition and construction would generate lots of solid waste. A recycling program would be required.